COLORADO SPRINGS —Frontier Airlines will end service from Colorado Springs to Denver, San Diego and Orlando, Fla., by early March, less than a year after the Denver-based low-fare carrier made the Springs a “focus city,” or small hub, with nonstop service to four western U.S. destinations.

Frontier is ending nonstop flights operated three days a week to San Diego on Feb. 21 and nonstop flights operated three days a week to Orlando on Feb. 25 because “the economics of the route did not justify ongoing service,” Kate O’Malley, a Frontier spokeswoman in Denver, said in an e-mail Monday.

The carrier will halt nonstop flights to Denver on March 2 as a result of reducing its fleet of 99-seat Embraer E190 aircraft as it continues to “look at making our network more profitable,” leaving Frontier without “a suitable aircraft in our fleet to operate the route,” she said.

Nonstop flights to Los Angeles and Phoenix from the Springs will continue on Frontier, O’Malley said, though beginning in February the carrier is reducing the Phoenix route from daily to five days a week and the Los Angeles route from six to three days a week.